Dispersants comprising terminal basic groups, such as, poly(lower alkylene)imine chains are well known and are generally prepared by reaction of the polyimine with polyester chains containing terminal acid groups, the reaction results in a mixture of amide and salt forms. U.S. Pat. No. 4,224,212 discloses dispersants comprising a polyester derived from a hydroxycarboxylic acid with at least 8 carbon atoms reacted with a poly(loweralkylene)imine. Dispersants of this type may be effective in non-polar media, such as, aliphatic solvents and plastics. EP208041 discloses dispersants comprising a polyester derived from ε-caprolactone reacted with a poly(loweralkylene)imine. These dispersants may be effective in more polar media, such as, ketones and esters. However, it would be desirable to have a dispersant which are capable of dispersing a particulate solid in both a polar and a non-polar organic medium. The present invention provides such a dispersant and compositions thereof.
U.S. Pat. No. 4,865,621 discloses motor fuel compositions comprising the reaction product of a dibasic acid anhydride, a polyoxyalkylene monoamine and a hydrocarbyl polyamine having a number average molecular weight of up to 1343.
International Publication WO05/010109 discloses a dispersant comprising the reaction product of a dibasic acid anhydride, a polyoxyalkylene monoamine and a hydrocarbyl polyamine having a number average molecular weight of not less than 1800.